CALIBRATION AND MEASURING TOOL

Abstract: This invention relates to a tool for calibration including a number of measuring projections arranged one after the other. The novelty lies in that the projections (5a-5k) each of one extends from a plate (7) to be slid on and secured to a rod structure, are localized in such a way around a central axis that at each projection is aligned another projection at another plate (4), said another plate having more than one projection in the same plane (5) and being mounted at the one end of the tool and in that the plates (7) are arranged in such a way that the projections (5a-5k) thereof together form a helical path along and around the tool.

Description: CALIBRATION AND MEASURING TOOL Technical field of the invention This invention relates to measuring and calibration tools and especially to such tools for calibration of for instance slide gages, micrometer calibrators, fixed gages and the like. Background of the invention For calibration purposes there are today a number of different tools the majority of which includes a rod shaped part and a number of projections aligned along the rod wherein reference surfaces are localized on either or both sides of said projections. There are tools having essentially even pitch between the projections/reference surfaces and such where the distance between the reference surfaces varies according to set patterns. The known devices are adapted for calibration of measuring tools of a certain kind but are normally not utilzed for just any measuring devices for instances such for internal measuring. Summary of the invention One aspect of the invention is to bring about a new type of calibration tool arranged in such a way that it can be used for practically all kinds of calibration or measuring tools and is easy to handle and operate without demanding specified supports. The background for the invention is a demand for a universally useful calibration tool. It is to be possible to make a calibration in a simple and safe way of practically every kind of measuring devices utilized within the industry and with a minimum of trouble allow also switching between measuring devices shaped in different ways. The new calibration tool includes a number of rigidly mounted plates separated by spacers or pads and localized one after the other, the majority of the plates having one projection and at least one plate having several, preferably four projections, which plate projections at least on one side has a reference surface facing in a longitudinal direction of the tool. The plates with the projections are fixedly arranged along a common carrier wherein the projections are oriented in such a way that the towards or from each other facing surfaces of two projections aligned with each other define a given distance of calibration. But for the plate or plates having several projections the plates are preferably localized in such a way that the projections essentially follow a helical line along the tool. Brief description of the drawings A preferred embodiment of the tool according to the invention will be described in the following with reference to attached drawings, in which Fig. 1 is a sideview showing the calibration tool from one side. Fig. 2 is another sideview showing a support device for the tool. Fig. 3 is an axial view of a plate having four projections, and Fig. 4 is a similar view showing a plate having one projection. Detailed description of preferred embodiment A calibration tool as unit designated 1 is constructed round and along a central rod, not shown, having threaded ends and on this rod the parts mentioned below are mounted. At the one end of the rod an end nut 2 is threaded and secured. A support pad 3 is placed against said nut and a first plate 4 having four projections 5 is slid on top thereof. After the first plate 4 a spacer sleeve 6 having a defined length and a plate 7 with a reference surface projection 5a, and furtheron in turn spacer sleeves 6 and plates 7 with reference surface projections 5b-5k are mounted until the intended number has been reached, whereupon a further pad is mounted and the stack of spacers and plates and sleeves is tightened rigidly by means of an end nut 2 arranged at the opposite end of the rod. During the mounting the rod may be placed between four guiding rods ensuring a correct aligning of the various projections. The first reference surface plate 4 has projections 5 projecting in all four directions and said projection can have carefully machined reference surfaces R on one or both sides. The single projection 5a of next plate, which projection may have a reference surface R on the one or both sides will be directed in the same direction as one of the four projections of the first plate and the following plates have their projections 5b-5k displaced 90° relatively to adjoining plates so that the projections will follow a helical line. In this way a considerable number of measuring or calibration spaces are created for control of measuring devices both for external and internal measuring, wherein in spite of the great number of calibration spaces all spaces are easy to reach. Even if you normally start at the plate 4 having several projections it is possible to mark the distances between pairs of projections extending in the same direction so that these can be used as calibration positions. The tool 1 is intended to be supported by the stand device 8 shown in Fig. 2 which includes a base plate 9 and two end pillars 10 having recesses 11 in which the nuts 2 arranged at each end of the tool are intended to rest. A calibration tool resting against the pillars 10 is easily turned until projections appropriate to or fitting a certain calibration object and furtheron the tool 1 during the calibration work need not be removed from the pillars, lifted, turned and turned over implying the risk for mechanical damage the settings and for thermical bias due to the heat of the users hands. The person performing the calibration thus leaves the tool resting on its stand the whole time, just makes it rotate relatively to the pillars if necessary. The embodiment shown and described is one of several possible. Instead of using as shown a first plate 4 having four projections it is possible to have a plate with two, three or more than four projections. The possible number is dependent on the circumference taken at the projections and consequently you may have a greater number of projections at the first plate to cooperate with a corresponding greater number of separate projections at the other plates if the diameter or circumference is increased. On the drawing there is shown a plate having several projections at the one end only. It is, of course, possible to have such a plate at each end of the rod and it is also as a further alternative possible to have plates presenting several projections at the one or both ends and one or several along the length of the rod. In the latter case it may be practical to arrange the projections cooperating with one of the plates having several projections for internal measuring whereas the others are arranged for external measuring, wherein in the former case the outwardly facing sides are carefully machined whereas in the latter case the inwardly facing surfaces are the one most carefully machined.

Claims: C L A I M S 1. Calibration and measuring tool wherein along an essentially column or rod shaped supporting part or the like a number of protruding projections are arranged, each of which projections on at least one of its sides facing along the rod in either direction presents a carefully machined reference surface serving as one end point for a distance of reference or a reference length, the other end point of which is situated at a reference surface arranged at another projection longitudinally spaced from the former projection, c h a r a c t e r i z e d in that the reference surface projections (5a-5k) are arranged at holed plates (4,7) slid on to and rigidly secured to a rod or column like structure forming said supporting part, that between such plates (4,7) are arranged spacer sleeve means (6) determining the distance between the plates and the reference surfaces (R) thereon, that the reference surface (R) projections (5a-5k) are mutually angularily displaced around a central axis thereof so that at least one projection is aligned with a reference surface of each of two or more projections (5) arranged at a single holed plate (4) and in a common radial plane adjacent at least the one end of the tool and that the tool has abutment or bearing surfaces (3) received in recesses (11) of a stand device (10) allowing rotation of the tool in its essentially horizontal position. 2. Tool according to claim 1, c h a r a c t e r i z e d in that the projections (5a-5k) protruding from the plates are mutually angularily displaced so that they seen together lie in a helical path. 3. Tool according to claim 1, c h a r a c t e r i z e d in that besides a single plate presenting two or more in a common radial plane arranged projections (5) at one end of the tool there is at least one further such plate having two or more projections arranged in the same radial plane, axially spaced from the former one. 4. Tool according to claim 1 or 3, c h a r a c t e r i z e d in that a number of projections (5) in one and the same plane of the plate (4) is four. 5. Tool according to claims l, c h a r a c t e r i z e d in that the stand (8) includes pillars or the like (10) extending from a base plate (9) , and presenting the recesses (11) adapted to engage bearing surfaces on the nuts or the like (3) rod of the tool (1) to allow rotation of the tool around a horizontal axis.

Inventors: NYBRO LEIF, NYBRO, LEIF
Applicants: NYBRO LEIF, NYBRO, LEIF
Application year: 1994
Main classification: G01B3
IPC codes: G01B3